MySQL Add foreign key failed solution

MySQL Restart command:

Redirecting To/bin/systemctl Stop Mysqld.service
[Email protected] centos7share]# systemctl start Mysqld.service
[Email protected] centos7share]# mysql-uroot-proot123

MySQL Run SQL file: Source/mnt/hgfs/xxx.sql;

Failed to initialize the foreign Key association caused by SQL run:

: 35:31.428 ERROR jdbc.sqlonly 4. Statement.executeupdate (
Alter table1
Add index fk_atx28tyc1c6j00d5mi7e5xt9d (key_id),
Add Constraint fk_atx28tyc1c6j00d5mi7e5xt9d
Foreign KEY (KEY_ID)
References table2 (ID))
Java.sql.SQLException:Cannot Add foreign KEY constraint

To view table field properties:

Two different lengths of field types can cause a foreign key association to fail, using the following statement to modify:
ALTER TABLE name modify field Name field type [allow non-null];

MySQL Add foreign key failed solution